﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using Ionic.Zlib;
using fastJSON;

namespace px4uploader
{
    [Serializable]
    public class Firmware
    {
        public int board_id;
        public string airframe_xml;
        public int airframe_xml_size;
        public string magic;
        public string description;
        public string ardupilot_git_hash;
        public string image;
        public byte[] imagebyte;

        public int image_maxsize;
        public int flash_free;

        public string extf_image;
        public byte[] extf_imagebyte;
        public int extf_image_size;
        public int extflash_free;
        public int extflash_total;

        public string USBID;

        public int parameter_xml_size;
        public uint build_time;
        public string summary;
        public string nuttx_git_hash;
        public string version;
        public string parameter_xml;
        public int image_size;
        public string git_identity;
        public int mav_autopilot;
        public int board_revision;

        readonly uint[] crctab = new uint[] {
		0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
		0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
		0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
		0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
		0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
		0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
		0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
		0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
		0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
		0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
		0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
		0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
		0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
		0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
		0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
		0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
		0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
		0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
		0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
		0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
		0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
		0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
		0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
		0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
		0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
		0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
		0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
		0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
		0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
		0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
		0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
		0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d };
        readonly byte[] crcpad = new byte[] { 0xff, 0xff, 0xff, 0xff };

        public Firmware()
        { }

        public static Firmware ProcessFirmware(string path)
        {
            Console.WriteLine("Read File " + path);

            // read the file
            using (StreamReader f = new StreamReader(File.OpenRead(path)))
            {
                return ProcessFirmware(f);
            }
        }

        public static Firmware ProcessFirmware(StreamReader f)
        {
            Firmware fw = JSON.Instance.ToObject<Firmware>(f.ReadToEnd());
            f.Close();

            if (fw.image_size > 0)
            {
                byte[] data = Convert.FromBase64String(fw.image);

                MemoryStream imagems = new MemoryStream(data, true);

                ZlibStream decompressionStream = new ZlibStream(imagems, CompressionMode.Decompress);

                int size = fw.image_size + (fw.image_size % 4);
                fw.imagebyte = new byte[size];

                try
                {
                    decompressionStream.Read(fw.imagebyte, 0, fw.image_size);
                }
                catch { Console.WriteLine("Possible bad file - usually safe to ignore"); }

                Console.WriteLine("image_size {0} size {1}", fw.image_size, size);

                // pad image to 4-byte length
                while ((fw.imagebyte.Length % 4) != 0)
                {
                    Array.Resize(ref fw.imagebyte, fw.imagebyte.Length + (4 - (fw.imagebyte.Length % 4)));
                }
            }
            if(fw.extf_image_size > 0)
            {
                byte[] data = Convert.FromBase64String(fw.extf_image);

                MemoryStream imagems = new MemoryStream(data, true);

                ZlibStream decompressionStream = new ZlibStream(imagems, CompressionMode.Decompress);

                int size = fw.extf_image_size + (fw.extf_image_size % 4);
                fw.extf_imagebyte = new byte[size];

                for (int a = 0; a < fw.extf_imagebyte.Length; a++)
                {
                    fw.extf_imagebyte[a] = 0xff;
                }

                try
                {
                    decompressionStream.Read(fw.extf_imagebyte, 0, fw.extf_image_size);
                }
                catch { Console.WriteLine("Possible bad file - usually safe to ignore"); }

                Console.WriteLine("extf_image_size {0} size {1}", fw.extf_image_size, size);

                // pad image to 4-byte length
                while ((fw.extf_imagebyte.Length % 4) != 0)
                {
                    Array.Resize(ref fw.extf_imagebyte, fw.extf_imagebyte.Length + (4 - (fw.extf_imagebyte.Length % 4)));
                }
            }

            return fw;
        }

        public uint __crc32(byte[] bytes, uint state)
        {
            foreach (byte data in bytes)
            {
                uint index = ((state ^ data) & 0xff);
                state = crctab[index] ^ (state >> 8);
            }
            return state;
        }

        public int crc(int padlen)
        {
            uint state = __crc32(imagebyte, 0);

            for (int i = imagebyte.Length; i < (padlen - 1); i += 4)
            {
                state = __crc32(crcpad, state);
            }
            return (int)state;
        }

        public int extf_crc(int padlen)
        {
            uint state = __crc32(extf_imagebyte.Take(padlen).ToArray(), 0);

            return (int)state;
        }
    }
}